# Advanced Search & Gathering for Systematic Reviews

The **Gather** step is the foundation of your Systematic Review. It allows you to build a comprehensive body of evidence by running multiple search strategies in parallel, combining different data sources (like semantic questions, Boolean strings, and Clinical Trial registries) into a single, reproducible protocol.

Unlike a standard search, the Gather workflow is designed for iteration. You can test different queries side-by-side, review your search history, and curate exactly which strategies feed into your final screening.

## 1. Running Multiple Searches (Multi-Tab Workflow)

In a rigorous review, a single search query is rarely enough. The Gather interface allows you to layer multiple search strategies to ensure you don't miss key papers.

To add a new search strategy, locate the **Paper sources** bar at the top of the interface and click the **+** icon to open a new tab. Choose your search method:

- **Question Search:** Best for natural language exploration.

- **Keyword Search:** Best for precise Boolean strings.

- **Upload Papers:** To include PDFs you already possess.

**Why use multiple tabs?**

- **A/B Testing:** Keep your original search in "Tab 1" as a control. Create "Tab 2" to test a variation of your query.

- **Combining Methodologies:** Have one tab for broad semantic discovery and another for a strict Boolean string. Elicit automatically de-duplicates papers across all active tabs.

- **Keyword-Exclusive search strategies:** When using Elicit as part of something like an HTA filing, using a variety of keyword searches is standard practice.

## 2. Iterating & Using Search History

You can update the text in any search bar and click **Update search** to refresh the results. Click the **History** button next to the Filters bar to open a log of previous queries run in that tab, allowing you to restore a past search strategy instantly.

## 3. Using Boolean Logic & Specific Corpora

**Keyword Search (Boolean Logic):** If you select **Keyword Search** from the **+** menu, you can enter precise Boolean strings using operators like `AND`, `OR`, and `NOT`. For example: `("type 2 diabetes" OR "diabetes mellitus") AND (mortality OR survival)`. For a full guide, see [Keyword search in Systematic Reviews](https://support.elicit.com/en/articles/14759156).

**Searching Specific Databases (e.g., Clinical Trials):** Click the **Source** dropdown (top left of the search bar) and select **Clinical trials** to search registries like [ClinicalTrials.gov](https://clinicaltrials.gov/) and access trial-specific filters.

## 4. Managing Scope (Removing Tabs)

All papers found in the tabs currently open in your "Paper sources" bar will move forward to the Screening step. If you decide a search strategy isn't working, click the **X** on that search tab to close it and exclude those results from your review.

**Warning:** Closing a tab removes those search results from your systematic review entirely — they will not appear in Screening, Extraction, or the final PRISMA diagram.

## 5. Automated Reporting & PRISMA

The Gather workflow self-documents. When you proceed to **Generate report**, Elicit will automatically:

- **Generate a PRISMA flow diagram** visualizing how many papers were identified from each specific search tab/source.

- **Document Methods** listing the exact query strings and Boolean logic used for every active tab, alongside the date and database source.